Whereas that kind of thing used to work, you must now use document exclusively like this :

jQuery(document).ajaxStop(function(){
// some code
});

The only exception is :

jQuery(function() {
// some code
});

Which will always work.

There is the jQuery compatibility library to point people with jQuery 1.4 to and that might make the connector work until you fix the connector to work with 1.4.x.

One last gotcha is that the jQuery team have switched to closure, so you might want to investigate CKEditor doing the same to increase compatibility and reduce the risk of bugs.
(Just don't use closure's advanced mode. It's a nightmare.)